Globe for incandescent electric lamps



(No Model.) RTLETT.

GLOBE FOR INOANDESGENT ELECTRIC LAMPS. No. 285,784. Patented Oct. 2,1883.

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- UNITED STATES PATENT ()EEIGE.

GEORGE P. BARTLETT, OF \VOBURN, MASSACHUSETTS.

GLOBE FOR INCANDESCENT ELECTRICLAMPS.

SPECIFICATION forming part of Letters Patent No. 285,784, dated October2, 1883.

' Application filed May 7, 1883. (No model.)

To all whom, it may concern.-

Be it known that I, GEORGE P. BARTLETT, of \Voburn, county of Middlesex,State of Massachusetts, have invented an Improve ment in Globes forElectric Lamps, of which the following description, in connection withthe accompanying drawings, is a specification, like letters on thedrawings representing like parts.

My invention relates to a globe for electric lamps, and has for itsobject to refract the rays, so as to vary the distribution of lightproceeding from the lamp, and also, if desired, to give a tint or colorto the light.

The invention consists, essentially, in the usual globe inelosing theluminous part of the lamp, and a setondary globe surrounding andinclosing the same, the space between the said globes being filled withany desired fluid for refracting or imparting a color to the lightpassing through, in combination with a collar and filling common toboth, and connecting them, as hereinafter specified and claimed.

The drawing shows in vertical longitudinal section an electric lampprovided with a globe embodying this invention.

The globe a and filament b therein, constituting the luminous part, maybe of any usual construction, one end of the said filament be ing shownas electrically connected with a threaded metallic collar, 0, adapted toscrew into a suitable socket, and attached to the globe o in anysuitable manner, as byacement filling, d. The said collar o'is shown inthis instance as provided with a flange, 6, adapted to receive and holdthe mouth of an inclosingglobe, f, similar in general outline to theglobe a, but larger than it, so as to leave a space of varying thicknessbetween the said gl obes,the said space being filled with a fluid, bywhich the light may be refracted, and, if desired, may have a tint orcolor imparted to it. As shown in this instance, the space between theglobes a and f gradually increases toward the points 2, the saidcompound globe thus acting as a lens to concentrate the rays in ahorizontal direction, or cause a larger amount of light than usual topass laterally from the globe, the amount of light being diminishedabove and below the said globe. The collar 0 serves to close the mouthof the outer globe, and the opening between it and the inner globe istightly sealed, so as to prevent the escape of the fiuid. The two globesare seeurely heldin the proper position relative to one another by thecollar 0. If desired, the relative shape of the two globes might bevaried so as to concentrate the light in any desired direction.

I am aware that lenses consisting of walls of glass filled with a fiuidhave been used in connection with artificial lights, and do not broadlyclaim such a device.

I claim- 1. The globe a, inclosing the luminous part of an electriclamp, and a second globe, f, surrounding the same, with an interveningChitllb ber and a fluid filling in said chamber, combined with thecollar 0 and a eementitious filling for tightly connecting said globes,substantially as shown and described.

2. The globes a and f, combined with the collar 0, its flange c, and thefilling (7, to hold the globes in proper relative position, all combinedand arranged substantially as shown and described.

Intestimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORGE P. BARTLETT.

Vitnesses:

I Jos. P. LIVERMORE,

13. J. Norns.

